Abstract: Objective The aim of this study was to explore the evaluation of significant liver fibrosis (SLF) by ultrasonic shear wave elastography (SWE) in rats with carbon tetrachloride(CCl₄)-induced liver injury. Methods 52 male SD rats were randomly divided into control group (n=12) and experimental group (n=40). The liver injury model was induced by intraperitoneal injection of carbon tetrachloride for 4, 6, 8 and 10 weeks, with 10 rats sacrificed at each time. At end of each experiment, the rats were anesthetized for liver stiffness measurement (LSMs) by SWE. The blood routine and serum biochemical parameters were obtained for calculation of APRI and FIB-4. The LSM immediately after dead (LSMd) was performed again after execution. The liver fibrosis, steatosis and inflammatory activity were evaluated by pathological examination. The receiver operating characteristic (ROC) curve was applied to evaluate the performance of parameters in the diagnosis of SLF. Results The pathological examination showed F0/F1 non-significant LF(NSLF) in 18 rats, and > F2 SLF in 30 rats; the APRI score in rats with NSLF was (0.051±0.023), significantly lower than [(0.135±0.117), P<0.05], and the FIB-4 score was (0.132^-100±0.088^-100), significantly lower than [(0.245^-100±0.125^-100), P<0.05], the LSMs was(5.2±1.7)kPa, significantly lower than [(9.7±2.8)kPa, P<0.05] and the LSMd was (3.6±0.8) kPa, significantly lower than [(8.8±1.7) kPa, P<0.05] in rats with SLF; the areas under the ROC curve (AUC) by LSMs and LSMd in predicting SLF were 0.91 and 0.93, significantly higher than 0.75 by APRI or 0.69 by FIB-4, with the sensitivities and specificities of 76.7% and 87.5%, and 85.7% and 92.0%, respectively. Conclusion The SWE technique has a high clinical value in evaluating LF in rats with CCl₄-induced liver injury, with the advantages of non-invasive, simple and repeatable feature.

Key words: Liver fibrosis, Shear wave elastography, Liver stiffness measurement, Diagnosis, Rats